That would be my first suspect too, John.
pat, K9JAUAt 08:40 PM 6/25/2015, you wrote:
>  I'd bet it's the coil of extra coax. Any time I ever dealt with a coil of
>extra coax, it's caused some sort of similar problem unless it's the 10
>turns at the feed point to the antenna some antennas like. Other than that,
>I've seen more than one coil of extra coax, and not once has it ever led to
>anything good..
>----- Original Message -----
>From: "Tom Behler" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Thursday, June 25, 2015 9:16 PM
>Subject: Interesting Problem With Alpha Delta DXCC Antenna Out Here At The
>RV Camp Site
>
>
> >               Hello, again, all.
> >
> >
> >
> > Well, my Alpha Delta DX CC antenna is  finally up out here at the RV camp
> > site.
> >
> >
> >
> > It is up a good 30 feet in the trees, with the  center and ends being at
> > about the same height.
> >
> >
> >
> > I have done some preliminary testing of the antenna, and all looks good,
> > with one exception.
> >
> >
> >
> > Specifically, the antenna tunes with the TS480 internal auto-tuner across
> > the 10, 15, and 40-meter bands.  It even tunes across much of 80 meters,
> > from about 3600 to about 3900 KHZ.
> >
> >
> >
> > However, I cannot get it to tune at all on 20 meters, once again, using
> > the
> > TS480 internal auto tuner.  I even put my MFJ auto-tuner extender in line,
> > with no luck.
> >
> >
> >
> > This is a bit disappointing to me, since 20 meters is one of my favorite
> > field day operating bands.
> >
> >
> >
> > As I am scratching my head here to try to determine what might be going
> > on,
> > I have two theories.  First, it has to be understood that I am limited to
> > keeping the antenna within my lot space, and have to work with the
> > available
> > trees.  This means that the legs of the antenna are probably only about at
> > a
> > 60-degree or so angle from the center.  In other words, the antenna is
> > kind
> > of like a folded  dipole in some ways.  I wonder if this could be
> > de-tuning
> > the antenna on 20, although I'm not sure why it also would not bbe
> > de-tuning
> > it on the other bands I mentioned.
> >
> >
> >
> > My second theory has to do with my coax feed line.  It turns out that I
> > probably have about 40 extra feet of coax that I have coiled up underneath
> > my station operating area.  I wonder too if this might have something to
> > do
> > with the strange 20-meter behavior.
> >
> >
> >
> > Obviously, I'm happy that the antenna is usable on 10, 15, 40, and 80, so
> > I'm sure I'll have a good Field Day exxperience.  But, the 20-meter
> > problem
> > does puzzle me.
> >
> >
> >
> > Does anyone have any thoughts, or suggestions that I might try to get
> > things
> > working on 20 meters?
> >
> >
> >
> > Tom Behler: KB8TYJ
> >
> >
> >
> >